Front Tire Installation

[cywelchjr]

I thought I would post as there was considerable debate on the site about the proper procedure for front wheel installation on a standard, having to do with getting the forks spaced properly.

At that time it was stated by several that you were supposed to only bounce the front forks to insure proper spacing and make sure they are not binding. Well, looking up something else in the Yamaha shop manual, I happened to be at that section of the manual and so read the procedure. It states to bounce the forks several times, and then to "move the left side fork back and forth" to properly space the disk in the middle of the caliper bracket before tightening the axle cap nuts. This removes a puzzling issue for me, as when I take my front wheel off, the only way it doesn't drag on the bracket is if I move the left fork over a bit, which is as it turns out what the shop manual says to do. I wanted to make sure that the proper information was put out here for those who have NOT read the shop manual on this item.

[natemoen]

Very interesting. I will have to use the shop manual more-so than the clymer when I begin reassembled. Speaking of reassembled I need to get going, this week is freakin nice weather and I am missing out!

[bikerphil]

If you are going to align with the "bounce it a few times" method, the calipers must be off. My prefered method is to first make sure the tubes are paralell in the triple trees using a plate glass against the front of them. Then with the springs out, lift the front wheel and compress the tubes and then tighten the pinch bolts. You will probably find that the rotor isn't exactly centered, but in it's happy space. This method might be a bit overkill, but it will give you the least amount of fork stiction.

[crazy steve]

I'm with Phil on this one; I'd much rather have smoothly working forks than worry if the rotor is exactly centered in the caliper bracket. I'd shim/mill the caliper brackets if I had to...

[bikerphil]

Oh, and once you find the sweet spot where the clamp likes to be on the axle, take a precise measurement off the speedo hub for future reference. My Special likes it's clamp side rotor .025" from the caliper bracket.

[cywelchjr]

Except the shop manual SPECIFIES to do this. This is not something I made up, and it shows a diagram of how they are supposed to be, and it's the bracket not the calipers themselves. Yamaha would NOT have specified this procedure if it was not needed, and I have had to do the same exact adjustment with two sets of forks, and the bounce test shows that they do NOT stick even the least bit. I'll stick with how the manufacturer said to do it, it's how they designed it to be done.

The only time I'll do things different than the manufacturer says to do it is if it can be demonstrated that it doesn't work, and this clearly works, I do have to adjust them when putting the front wheel on, and they do NOT stick or hang. They have been checked for being straight as well (this was checked OFF the bike) and both sets are straight. There is a reason this is outlined in the manual, it's needed (at least sometimes). Would I move it on every bike I put the front wheel on, no, not if the rotor is reasonably spaced in the bracket. This MIGHT be the reason for seeing different dishing on some of the brakes disks is different, this might have been something that was adjusted on some to make this adjustment as minimal as possible.

I discovered the need the very first time I removed the front wheel, and since it's part of the procedure in the shop manual, I'll continue to do what the manufacturer recommends. You may choose to do different, but I also was not happy with the fit of speedo drive to the fork, but after I moved the forks slightly closer together I felt it was the way it was supposed to be (it was just barely engaged before). And as I said, there is no binding of the forks, they work just fine.

As I said, I'll do what the book says, you may choose to ignore the instructions as you wish.

(yes I know we have the example of the grease fitting for the shaft, but his is something that I was able to SEE the described issue, this is NOT the same).

[cywelchjr]

Oh, and once you find the sweet spot where the clamp likes to be on the axle, take a precise measurement off the speedo hub for future reference. My Special likes it's clamp side rotor .025" from the caliper bracket.

Oh, and I'm talking specifically about the standard here, I didn't see any reference to the special, as I didn't look at the addendum, just at the base information which is what applies to my standard.

YMMV with a special.

[crazy steve]

Except the shop manual SPECIFIES to do this. This is not something I made up, and it shows a diagram of how they are supposed to be, and it's the bracket not the calipers themselves. Yamaha would NOT have specified this procedure if it was not needed, and I have had to do the same exact adjustment with two sets of forks, and the bounce test shows that they do NOT stick even the least bit. I'll stick with how the manufacturer said to do it, it's how they designed it to be done.

Yep, the FSM does specify this. This is basically to correct a design flaw and/or poor quality control in the machining of the various parts. If everything fit the way it was supposed to, or if Yamaha had given a bit more clearance in the caliper bracket, this wouldn't be needed. I'd prefer not force one thing out of alignment to gain alignment on another part, but would much rather do a bit more work and get everything aligned right.

You have the same procedure for the special forks too, but there you don't have any choice; the brake design prevents you from correcting it by other means.

If factory manuals were the Holy Grail, all these bikes would still be stock...

[cywelchjr]

Yep, the FSM does specify this. This is basically to correct a design flaw and/or poor quality control in the machining of the various parts. If everything fit the way it was supposed to, or if Yamaha had given a bit more clearance in the caliper bracket, this wouldn't be needed. I'd prefer not force one thing out of alignment to gain alignment on another part, but would much rather do a bit more work and get everything aligned right.

You have the same procedure for the special forks too, but there you don't have any choice; the brake design prevents you from correcting it by other means.

If factory manuals were the Holy Grail, all these bikes would still be stock...

Unfortunately I'm afraid that the problem may be in the trees rather than lower down, and with the gap I see at the speedo gear, it would require adding shims there as well. I believe that's part of the reason for the bounce part of the process. That said, to actually fix the problem would from what I can tell require fixing the problem in the trees, which would be far more involved. For the small movement needed to get it right, and the fact that my forks made it 30 years without issue (the only reason I changed them was because I couldn't get the caps off to change the seals), and the replacements being the same age made it the same time, but maybe less miles. I know mine made it at LEAST almost 100k, either that or almost 200k, and that tells me there can't be too much wrong with the procedure if they last that kind of mileage. Mods are certainly appropriate if you can improve something or or because of a shortcoming, but changing something that works just because you don't like it? That just seems like crazy talk to me.

Frankly just like the specials, if the gap is too far off, you don't have a choice without modifying the forks or the caliper mounts. If mine left enough clearance without moving them I personally wouldn't bother. However with the caliper frame rubbing on the rotor there wasn't much choice in the matter. It may be that it doesn't matter most of the time, but based on 80,000+ miles on the original forks and them still being just fine, I can see evidence of there being any issue with the procedure unlike the FD coupler where you can see that it doesn't get grease in that joint.

[bikerphil]

Cy, since you have been lucky and not had any handling issues, by all means use the FSM alignment procedure. Some of us unfortunately have had to resort to a more precise alignment procedure to get things working right. There should be a gap between the speedo drive and the fork leg. The shoulder on the axle itself keeps it tight.